2,4-dichloro-3,5-xylenol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Justification for type of information:

N/A

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

OECD 476

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Principles of method if other than guideline:

As guideline

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Justification for non-LLNA method:

N/A

Test material

Test material information

Constituent 1

Reference substance name:

4-chloro-3,5-xylenol

EC Number:

201-793-8

EC Name:

4-chloro-3,5-xylenol

Cas Number:

88-04-0

Molecular formula:

C8H9ClO

IUPAC Name:

Phenol, 4-chloro-3,5-dimethyl-

Test material form:

solid: crystalline

Details on test material:

Sponsor's identification
Description
Batch number
Date received
Storage conditions
PCMX
cream coloured, crystalline solid
285/13847
27 September 2001
room temperature, in the dark

Specific details on test material used for the study:

2. TEST MATERIAL
Sponsor's identification
Description
Batch number
Date received
Storage conditions
PCMX
cream coloured, crystalline solid
285/13847
27 September 2001
room temperature, in the dark

In vitro test system

Details on the study design:

The technique
used is a fluctuation assay using microtitre plates and trifluorothymidine as the selective agent and
is based on that described by Cole and Arlett (1984). Two distinct types of mutant colonies can be
recognised, ie. large and small. Large colonies grow at a normal rate and represent events within
the gene (base-pair substitutions or deletions) whilst small colonies represent large genetic
changes involving chromosome 11 b (suggesting clastogenic activity)

Results and discussion

Positive control results:

There was a reduction in the %RSG of cells exposed to the test material when compared to the
concurrent vehicle controls. in both the absence and presence of metabolic activation

In vitro / in chemico

Results

Key result

Run / experiment:

other: Toxicity

Parameter:

other: Toxicity

Value:

0

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Conclusion. The test material was shown to be mutagenic to L5178Y cells under the conditions of the test.

Other effects / acceptance of results:

The test material induced toxicologically significant, dose-related increases in the mutant
frequency at the TK +/- locus in L5 l 78Y cells in the presence of metabolic activation and was
therefore considered to be mutagenic under the conditions of the test.

Any other information on results incl. tables

The Relative Suspension Growth (RSG) data were as follows:

Dose % RSG (-S9) % RSG (-'-S9)

(μg/ml) 3-Hour Exposure 3-Hour Exposure

0 100 100

6.25 103 75

12.5 1()4 57

25 89 36

50 58 18

100 0 0

150 0 0

200 0 0

There was a reduction in the %RSG of cells exposed to the test material when compared to the

concurrent vehicle controls. in both the absence and presence of metabolic activation (S9).

Applicant's summary and conclusion

Interpretation of results:

Category 1A (indication of significant skin sensitising potential) based on GHS criteria

Conclusions:

The test material induced toxicologically significant, dose-related increases in the mutant
frequency at the TK +/- locus in L5 l 78Y cells in the presence of metabolic activation and was
therefore considered to be mutagenic under the conditions of the test.

Executive summary:

Conclusion. The test material was shown to be mutagenic to L5178Y cells under the conditions

of the test.